[off camera] NASA's been looking at snow from space for decades, but
NASA is in the field right now to learn a little bit more. Here to tell us a little about it is Dr.
Dalia Kirschbaum from NASA's Goddard Space Flight Center in Greenbelt, Maryland. Thank you for joining
us. [Kirschbaum] Thanks for having me. [off camera] NASA satellites see snow cover from space
how does this winter compare to previous years? [Kirschbaum] Well NASA's Earth observing
fleet can look at everything - look at our oceans, our atmospheres
and even over land where we can see snow. Now snow varies from year to year
and month to month. And one interesting thing we've observed is
out in the Sierra Nevadas. Two years ago we had snowpack that only one
quarter of normal. Now compare it to this year, we see 180 percent
of normal, the most in almost 20 years. And that's very important for understanding
our freshwater resources. [off camera] NASA scientists are in the field right now,
testing advanced technologies to measure snow like never before. What will
these new measurements tell us about snow? [Kirschbaum] Well NASA's been observing snow cover
from space for decades, but what we really want to understand is snow depth and how much
fresh water is stored. And that helps us to understand and forecast rive flow
and water availability. So a new snow campaign going on in Colorado
called SnowEx uses advanced airborne instruments to measure
these processes with the goal of ultimately putting this type of instrument on
a future satellite to look at global snow depth around the world.
[off camera] Can NASA see falling snow from space? [Kirschbaum] Yes.
Snow is tricky to measure, but the Global Precipitation Measurement mission or GPM
is specifically designed to look at snow layer by layer through the storm
even at the tops of hurricanes. And that if very important for improving
our weather forecasting and understand extreme events such as the one you see here
from GPM in 2015, a Nor’easter that went on to
effect New England. And having this vantage point of space is vital for
understanding not just what's happening over land, but over areas we don't see
much information from the ground such as over mountains and our oceans.
[off camera] Up to 70 percent of water resources in the western U.S. comes from
snowmelt. California has been getting heavy snow and rain recently. Is the drought
over there? [Kirschbaum] Well these huge atmospheric rivers that are coming off the
Pacific have dumped a tremendous amount of rainfall and snow at high altitudes in California
and this has gone a long way in alleviating the drought conditions. But that's
mostly at the surface. The groundwater takes a lot longer to replenish.
and is critical for irrigation. And that will take several more years of
an above average rainfall before it's back to normal. [off camera] How does snow
impact parts of the country that rarely see any snowfall? [Kirschbaum] Well if you go to
any grocery store, nearly half of the produce you see there actually came from the Central Valley
of California. And the water used to irrigate those crops that
originated for the most part in the Sierra Nevadas. So understanding how much snow
we have there has wide-reaching implications across the U.S.
affecting our produce. But that's only part of the story, a sixth of the world
relies on season snowpack
to better understand all of those processes from space.
[off camera] Where can we learn more? [Kirschbaum] You can go to snow.nasa.gov where
you can learn how NASA and its partners are uncovering advanced technologies to
understand snow in our backyards and around the world. [off camera] Thanks for joining us.
[Kirschbaum] Thanks for having me.